Moderate
Azithromycin × Quetiapine
Macrolides×Atypical antipsychotics
Mechanism
Additive QT prolongation (quetiapine prolongs QT at high doses).
Symptoms
QT prolongation on ECG. Dizziness, syncope, palpitations. Rarely: polymorphic ventricular tachycardia (torsades de pointes). Risk is higher with hypokalaemia, hypomagnesaemia, bradycardia, and ischaemic heart disease.
Management
For short azithromycin courses (3–5 days) with quetiapine ≤300 mg, the combination is acceptable. On high quetiapine doses or cardiovascular disease: ECG before start or alternative antibiotics.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.